Promoter-specific co-activation by Drosophila mastermind.
Mastermind (Mam) is a co-activator protein of binary complexes consisting of Suppressor of Hairless (Su(H)) and Notch Intracellular Domain (NICD) proteins assembled on cis-regulatory regions of target genes activated by Notch signaling. Current evidence indicates that Mastermind is necessary and sufficient for the formation of a functional Su(H)/NICD/Mam ternary complex on at least one specific architecture of Su(H) binding sites, called the SPS element (Su(H) Paired Sites). However, using transcription assays with a combination of native and synthetic Notch target gene promoters in Drosophila cultured cells, we show here that co-activation of Su(H)/NICD complexes on SPS elements by Mam is promoter-specific. Our novel results suggest this promoter specificity is mediated by additional unknown cis-regulatory elements present in the native promoters that are required for the recruitment of Mam and formation of functional Su(H)/NICD/Mam complexes on SPS elements. Together, the findings in this study suggest Mam is not always necessary and sufficient for co-activation of binary Su(H)/NICD complexes on SPS elements.
Cave
John W
JW
Department of Neuroscience, Weill Cornell Medical College, Burke Medical Research Institute, 785 Mamaroneck Ave, White Plains, New York, NY 10021, USA; Burke Medical Research Institute, White Plains, NY, 10605, USA. Electronic address: joc2042@med.cornell.edu.
Caudy
Michael A
MA
Department of Neuroscience, Weill Cornell Medical College, Burke Medical Research Institute, 785 Mamaroneck Ave, White Plains, New York, NY 10021, USA; Burke Medical Research Institute, White Plains, NY, 10605, USA.
D000818:Animals; D001483:Base Sequence; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics* / Q000378:metabolism; D019143:Evolution, Molecular; D005786:Gene Expression Regulation; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D017434:Protein Structure, Tertiary; D051880:Receptors, Notch / Q000235:genetics / Q000378:metabolism*; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*
D029721:Drosophila Proteins; C497759:N protein, Drosophila; D009687:Nuclear Proteins; D051880:Receptors, Notch; D012097:Repressor Proteins; C088731:Su(H) protein, Drosophila; C085316:mam protein, Drosophila